The present invention relates in general to dispersing agents for dispersing oil and other petrochemicals from the surface of bodies of water, and in particular to a new and useful dispersant which is water-based and avoids the use of petroleum distillates, the major solvent in all currently US EPA approved oil spill dispersants.
There are two basic mechanisms for dealing with an oil spill on a body of water, such as crude oil from a tanker at sea. One is to try and recover the oil and the other is to disperse the oil. Recovery has proven to be extremely ineffective in that only a small portion of the oil is actually recovered, allowing the rest to reek havoc on nearby shorelines and wild life.
Currently, the United States Environmental Protection Agency (EPA) permits the use of only four commercially available dispersants to disperse oil spills. Two of them are known by the trade name COREXIT and are available from Nalco/Exxon Energy Chemicals, LP. of Sugar Land, Tex. COREXIT 9597 and the more recent COREXIT 9500 compositions both contain a large percentage of petroleum distillates. The other two permitted dispersants are known by the trademarks NEOS AB 3000 for a hydrocarbon solvent based dispersant available from NEOS Company Limited of Kobe, Japan, and MARE CLEAN 200, also based on hydrocarbon solvents and available from Taiho Industries Co., Ltd. of Tokyo, Japan.
The use of mineral spirits and other hydrocarbon based dispersants is counterproductive in that it adds to the loading of the ocean with compounds of the same petrochemical class as the spill itself.
The dispersing effect of a dispersant must also be balanced against its toxicity to fish and other wild life.
U.S. Patent 5,399,350 to Potter, assigned to Nurture, Inc., discloses a proteinaceous oil spill dispersant. Reference is made in this patent to two water-based dispersants, one identified by the trademark ATLANT'OL AT-7, available from Aspra, Inc. and the other known by the trademark OMNI-CLEAN OSD, available from Delta Omega Technologies. Delta Omega Technologies is also the assignee of U.S. Pat. No. 5,308,550 for a cleaning and wetting agent and solvent.
U.S. government regulations that dictate the characteristics of an acceptable dispersant with regard to effectiveness and toxicity, are found in 40 CFR .sctn. 300.900 and following sections. Comparative tests following the protocol of these regulations are appear later in this disclosure in a section entitled TESTING OF DISPERSANT EFFICIENCY.